Compounds of general structure I ##STR1## wherein Ar represents an aromatic (substituted or unsubstituted) or heteroaromatic (substituted or unsubstituted) ring system exhibit herbicidal activity against a variety of weed species.
While some of the compounds in this family may be prepared by a conventional, convergent approach via the requisite substituted 2-amino-1,2,4-triazolo [1,5-a]pyrimidine, as described in copending application Ser. No. 574,232 filed Jan. 26, 1984, many analogs cannot be made following this approach. The highly insoluble nature of many of the appropriate substituted 2-amino-1,2,4-triazolo[1,5-a]pyrimidines prohibit their reaction with the less reactive and less stable aromatic sulfonyl chlorides.